Systems designed for ensuring security and privacy can be used with a variety of applications. Such applications traditionally include the regulation of entry to, and mobility within, a person's residence or workplace, but can also include controlling access to a person's computer, vehicle, bank account, or other property.
Generally, these systems are premised on the idea of confirming the identity of a person as that of an authorized person or user before granting access to whatever the system is designed to protect. Typically, a security system solicits an identifier from a person, and the person in turn responds by providing such an identifier. A comparison is then made between the provided identifier and an identifier that is stored by the system and associated with the person's profile. If a correct match is made, access or entry is granted.
In the past, security systems have typically incorporated the solicitation of a password or other random key that is unique to an authorized person and which in theory only the authorized person knows or possesses. Some of the problems associated with passwords and keys, however, include the fact that they can be forgotten by, or otherwise become unavailable to, the authorized person. Furthermore, they can be discovered by, or otherwise be made known to or become possessed by, an unauthorized individual.
Security systems have also incorporated the solicitation of biometrics in their design, either alone or in conjunction with the solicitation of passwords or random keys. Some of the advantages of using biometrics include the fact that if properly selected, biometrics serve as relatively more precise and unique identifiers of a person and do not require active memory or possession of the identifier on the part of the person. Additionally, because properly selected biometrics are uniquely identifiable with only one specific person, the likelihood of falsifying or misrepresenting a person's biometric is relatively small. Biometrics that are currently used in security systems include superficial anatomical traits, for example fingerprints, hand and face geometries, and retinal patterns; cardiac parameters; metabolic parameters; vocal parameters; or other physiological characteristics.
The combination of a password and/or key, and a biometric adds to the reliability of identifying a unique individual. Even if all three parameters are incorporated, however, such a system may still be vulnerable to corruption. In a military setting, for example, an enemy combatant could steal the key from an authorized person, torture the person to acquire the password, and remove the person's finger to obtain the fingerprint biometric thereon, and thus potentially gain access to a military computer system.
Physiological data can be derived from a wide variety of physiological monitoring systems designed for, e.g., in-hospital use, in-clinic use, ambulatory use, or the like. Without limitation or prejudice, however, the following description is largely in terms of preferred monitoring systems for ambulatory use.
In order to perform normal daily waking and sleeping activities, a monitored subject should be constrained no more than necessary. In preferred embodiments, therefore, physiological sensors are attached to, affixed to, carried by, or incorporated in or as part of ordinary wearable items that are unobtrusive, comfortable, and useable without assistance. Suitable wearable items include garments, jackets, bands, patches, and the like, made from a variety of materials, particularly elastic materials to insure a snug fit; they can be donned in one piece or include zippers, Velcro, snaps, and the like, that are joined after donning. Sensors can be incorporated into garments in many ways, for example, by weaving, knitting, or braiding into a garment's fabric; or by being carried in, mounted in, or attached to the garment; also flexible sensors can be glued, printed, sprayed and so forth onto inner or outer garment surfaces. U.S. Pat. Nos. 6,551,252 and 6,047,203 disclose such garments. The entire contents of the references identified above are expressly incorporated herein by reference thereto. Citation or identification of the references listed above, or in any section of this application hereafter, shall not be construed as prior art to the present invention.
U.S. Pat. No. 5,719,950 describes a biometric authentication system that incorporates the solicitation of a specific biometric parameter, such as a fingerprint, and a non-specific biometric parameter, such as body temperature, electrocardiogram reading, or pulse. The non-specific biometric is selected to ensure that the individual seeking authentication is not incapacitated, dismembered, or deceased.
U.S. Pat. No. 6,483,929 describes a method and device for authentication using physiological and histological biometrics of a person, including fingerprints, muscular-skeletal dimensions, oxygen and carbon dioxide content in tissue, cardiac cycles, dilatory response of the eye, and other responses of the nervous and metabolic systems to applied stimuli.
Thus, there remains a need for a method of identity authentication and confirmation that measures as a biometric the unique set of multiple physiologic parameters and characteristics of a person, including for example respiratory and cardiac parameters.